--- Have you solved your problem?---I've kept on thinking about that matter ______, but I have no idea yet now.
She can play _____ guitar, but she can’t play ____ chess.
Bob often _______ two hours ________ his homework.
----May I speak to the headmaster? ----He ______ a meeting now. Can I take a message?
----Would you like some noodles? ----______, I am full..
She _____ medium height and _____ short hair.